On Thu 2019-10-10 10:35:39, Greg Kroah-Hartman wrote: > From: Li RongQing <lirongqing@xxxxxxxxx> > > commit e430d802d6a3aaf61bd3ed03d9404888a29b9bf9 upstream. > > The reason is that the code in collect_expired_timers() uses jiffies > unprotected: > > if (next_event > jiffies) > base->clk = jiffies; > > As the compiler is allowed to reload the value base->clk can advance > between the check and the store and in the worst case advance farther than > next event. That causes the timer expiry to be delayed until the wheel > pointer wraps around. > > Convert the code to use READ_ONCE() Does it really need to use READ_ONCE? "jiffies" is already volatile, READ_ONCE just adds another volatile... Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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